An oven, such as a microwave oven or a combination oven which, for example, combines microwave cooking with other forms of cooking (e.g., convection cooking), typically includes an oven body and an oven door. The oven body defines an oven chamber within which food may be processed, and the oven door interacts with the oven body to permit access to the oven chamber.
A typical oven door, which is used on a microwave oven, has a window, usually in the form of a screen, for preventing leakage of the microwave RF energy that is generated by the oven to process the food in the oven chamber. The function of the screen is to attenuate the RF energy, which would otherwise leak through the oven door, to a level that meets government and/or industry standards. At the same time, the screen must be transparent enough to permit a user to view the contents of the oven chamber when the oven door is closed and the oven is processing food.
Unfortunately, if the screens of current oven doors are made transparent enough to be satisfactory to users, the oven doors do not sufficiently attenuate RF energy. Accordingly, unacceptable levels of RF energy leak through such oven doors. On the other hand, if sufficient RF energy is attenuated by the screens so that unacceptable levels of RF energy do not leak through the corresponding oven doors, the screens of current oven doors are not transparent enough to be acceptable to users. Accordingly, an oven door having excellent visibility is not practical when a single metal mesh is used as the only means to attenuate RF energy.
The present invention is directed to an oven door which is transparent enough to provide excellent visibility to users and which attenuates RF energy to an acceptable level.